Change labels for Job classes in Local KB Import UI

Purpose:
In the Local KB Import UI the labels "JSON Harvester" and "JSON File import" are used to describe the jobs with classes org.olf.general.jobs.PackageIngestJob and org.olf.general.jobs.PackageImportJob respectively. These labels are not completely accurate.

The purpose of this story is to improve the labelling in the UI to make it clearer to the user what these are.

The changes to be made are:
In the Search and Sort filter options, change the labels for the "Job type" filters as follows:

• JSON Harvester -> Harvester
• JSON File import -> File import

In the job view pane:

• Change the label for the "Source" field to "Job type"
• Change the display value "JSON Harvester" -> "Harvester"
• Change the display value "JSON File import" -> "File import"